Question

Can you please let me know why the following piece of code is not working, I am getting the error message when the debugger past the variable “strStatus”. The error message is: “Object reference not set to an instance of an object.” Can you please help. Thanks – Yagya

    protected void Button1_Click(object sender, EventArgs e)
    {
        if (Y0130_chkNew.Checked == true)
        {
            bool isChecked = true; // This is required for later retrieval.

            string strAction = "Reporting";
            string strFromRole = ddSelectRole.SelectedValue;

            string TxtBoxID = myProject.getTextBox(strAction, strPath);
            TextBox txtb = new TextBox();
            txtb = (TextBox)Page.FindControl(TxtBoxID);
            string strStatus = txtb.Text;

            string ddID = myProject.getDropDown(strAction, strPath);
            DropDownList ddLst = new DropDownList;
            ddLst = (DropDownList)Page.FindControl(ddID);
            string strForwardRole = ddLst.SelectedValue;

            // Call the function now
            my.updateXML(strFromRole, strAction, strStatus, strForwardRole, strPath);

        }

    }

Answer 1

Page.FindControl(TxtBoxID); returns null what is the reason for your exception. FindControl does not search controls recursively, only in the given NamingContainer.

If the control is not nested in another NamingContainer on the page(f.e. a GridViewRow), there’s no reason at all to use FindControl since you could reference it directly:

string strStatus = TextBox1.Text; // assuming TextBox1 is declared on the aspx

If you’re using MasterPages the NamingContainer of controls in the ContentPage is not the page but the ContenPlaceHolder:

Cannot find TextBox on Page